To implement fork semantics, we need to customize the bootstrapping of
the newly created process, in particular the startup of the main thread.
The CPU session interface provides a suitable hook. By virtualizing the
CPU connection of the process to core, we can defer (and parametrize)
the startup of the main thread. Furthermore, this enables us to detect
illegal attempts by the Noux process to create threads in addition to
the main thread.
By letting Noux processes talk to service implementations local to the
Noux server, we can track RAM allocations and RM operations. This is
needed as a prerequisite to implement fork.
